1. Field of the Invention
The present invention relates to a wire-connection structure of a motor, comprising: an annular stator including coils of a plurality of phases, the coils being arranged alternately in a circumferential direction; bus rings of a plurality of phases, each of the bus rings being formed by a bent wire material into a substantially annular shape and arranged along the stator; windings of the coils of the same phase being arranged at predetermined intervals and wire-connected to each other by the corresponding bus ring.
2. Description of the Related Art
Japanese Patent Application Laid-open No. 2004-96841 discloses a structure of a direct-current brushless motor in which, in order to wire-connect ends of windings of a plurality of coils of U-phase, V-phase and W-phase constituting a stator respectively to U-phase, V-phase and W-phase bus rings fixed along a side face of the stator, wire-connection portions are provided so as to protrude in radially inward directions from the U-phase, V-phase and W-phase bus rings into a U-shape or double-wire overlapping shape, and windings of the U-phase, V-phase and W-phase coils corresponding to connection terminals fixed to the wire-connection portions by crimping are fixed by crimping to the wire-connection portions.
However, in the conventional structure, the wire-connection portions are provided by forming the wire materials of the U-phase, V-phase and W-phase bus rings into a U-shape or double-wire overlapping shape, thereby increasing the number of steps for processing the wire-connection portions is increased to increase the cost; and moreover, the wire-connection portion has a width of more than twice that of the wire material, thereby making it difficult to secure a space to insert a tool for crimping and fixing the connection terminal to the wire-connection portion to deteriorate workability.